On Sun, Apr 07, 2024 at 07:57:40PM +0200, Lukas Wunner wrote: > Add a DEFINE_FREE() clause for x509_certificate structs and use it in > x509_cert_parse() and x509_key_preparse(). These are the only functions > where scope-based x509_certificate allocation currently makes sense. > A third user will be introduced with the forthcoming SPDM library > (Security Protocol and Data Model) for PCI device authentication. > > Unlike most other DEFINE_FREE() clauses, this one checks for IS_ERR() > instead of NULL before calling x509_free_certificate() at end of scope. > That's because the "constructor" of x509_certificate structs, > x509_cert_parse(), returns a valid pointer or an ERR_PTR(), but never > NULL. > > Comparing the Assembler output before/after has shown they are identical, > save for the fact that gcc-12 always generates two return paths when > __cleanup() is used, one for the success case and one for the error case. > > In x509_cert_parse(), add a hint for the compiler that kzalloc() never > returns an ERR_PTR(). Otherwise the compiler adds a gratuitous IS_ERR() > check on return. Introduce an assume() macro for this which can be > re-used elsewhere in the kernel to provide hints for the compiler. > > Suggested-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > Link: https://lore.kernel.org/all/20231003153937.000034ca@xxxxxxxxxx/ > Link: https://lwn.net/Articles/934679/ > Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> > --- > Changes v3 -> v4: > Use passive mood in and drop the word "handy" from commit message (Jarkko). > > Link to v3: > https://lore.kernel.org/all/63cc7ab17a5064756e26e50bc605e3ff8914f05a.1708439875.git.lukas@xxxxxxxxx/ > > crypto/asymmetric_keys/x509_cert_parser.c | 43 ++++++++++++------------------- > crypto/asymmetric_keys/x509_parser.h | 3 +++ > crypto/asymmetric_keys/x509_public_key.c | 31 +++++++--------------- > include/linux/compiler.h | 2 ++ > 4 files changed, 30 insertions(+), 49 deletions(-) Patch applied. Thanks. -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
